Volatile
by aurimaedre
Summary: Molly comes to 221B and finds out that Sherlock has acquired some equipment from Barts that he shouldn't have and lectures him. Slightly steamy.


**Disclaimer: I don't own anything**

Sherlock was standing in front of his most recent experiment when he heard someone walking up the stairs of 221B. The footsteps were light but sounded weighted down so it wasn't John or Lestrade and Mycroft would text before ever setting foot into his home. Mrs. Hudson's canter was more of a shuffle and Mary's was usually more forceful (since she never wanted to be in his presence). This only left Molly to be the one gracing the stairs of his flat. She must have come by to up his biohazard waste, which would explain the weighted sound of her steps. She had started this pattern shortly after he returned when John started complaining about the unsanitary conditions of their fridge and apartment. When she found out she gave him a very forceful lecture and demanded that she be given access to 221B to recollect the parts and make sure he hadn't done anything that would require the efforts of WHO or the CDC. He immediately handed over a spare key, surprised and a little turned on by the pathologist's actions.

He had come to appreciate her visits after John moved out, she kept him grounded in the world and made sure he ate and slept, sometimes spending a few hours and helping with some of the his experiments. Today he was very grateful for the informal nature of her visits because she would just come in rather than wait to be invited and he couldn't step away from what he was currently doing. It was somewhat different than most of his usual at home studies. While he should have been conducting it at St. Barts Molly was off all weekend and he couldn't stand the drones that occupied the lab when she wasn't there. That and the fact that the information he would acquire was highly important, not to mention time sensitive, in his most recent case gave him no other choice but to conduct in within his walls.

He suspected that the liquid found in the victim's vodka bottle contained a lethal amount of methanol and with the analytical equipment that would make this testing easy being down he had to do a manual distillation. Their boiling points were only 14 degrees apart so it required a large amount of concentration. The methanol had already begun collecting in a collection flask and he had to make sure the temperature didn't spike without his knowledge or else his efforts the past hour would be useless.

He heard the door open and Molly come in, humming some upbeat tune that had become popular on the radio. She was in a good mood and he suspected that if turned around she would be performing so small dance moves as she made her way to his kitchen.

"Afternoon, Sherlock." Her voice was bubbly and it made his smile unconsciously.

"Hello, Molly." He replied, keeping his eye fixed on the thermometer. "I would give you a proper greeting but I am in the middle of something that requires my unwavering eyesight.

"Okay!" She didn't seem perturbed and started cleaning out his freezer.

"Sherlock, are the eyeballs done yet? I gave them to you a month ago and you keep refusing to let me take them back. They are pretty much useless to you now."

Sherlock lifted his hand and waved dismissively, indicating she could dispose of them.

"And this kidney?"

"Yes, that can go too. I am done with everything in there, you can take it all."

Molly gave a small cheer, "Good! We can finally clean this out and move it into the spare bedroom; you did still want to make that a lab space, correct?"

"Yes." He said shortly, the drops were becoming slower, more spaced out, meaning he was almost done. He gave a quick glance at the 100mL round bottom flask and noticed that it was half full. Good, he was, as usual, correct in his deductions. Methanol poisoning.

"You will need to go shopping for a new fridge tomorrow and no using this one to store anything other than food!"

He could hear her close her containers and take off her gloves. He was switching out collection flasks when he heard her approach him.

"What are you doing?" Her words had a suspicious air to them and held a slight amount of… anger to them?

"I was testing a hypothesis that has now proven to be correct. The victim died of, what appeared to be, methanol poisoning. However, there is no way the victim could have ever been exposed to it aside from murder. A quick visit to his home revealed that the victim liked to have a nightcap each night, his drink of choice being vodka on the rocks. The only way the killer could have poisoned the victim without the victim knowing something was wrong was to combine it with his favorite alcohol. When mixed appropriately, the taste of methanol and ethanol are not that distinguishable, something you are already aware of. The median lethal dose of methanol is around 100mL. It can be deduced that our killer was somewhat competent since he had access to methanol in the first place and would know that for the poison to be effective he would have to account for the whole bottle. Your average glass holds 200mL and the bottle at our victim's house was a 2L bottle, only opened once. This means that for there to be a lethal amount in the victim's glass the bottle would have to contain 50% methanol, also meaning that the bottle was given as a gift since it needed such a large amount. To confirm my theory I took 100mL of the tampered alcohol and distilled it, proving that it did indeed contain 50mL of methanol." He finished and turned to smile at Molly, thinking she would once again be amazed at his intellectual prowess.

What he was met with, instead, was Molly's glare. "Don't you see, Molly! I solved it in less than a day! And Lestrade said it was a 7… even Anderson could have solved this one!" He scoffed.

Her glare seemed to deepen rather than turn into a smile. He didn't understand her reaction… usually she demonstrated glee when he managed to solve a case this quickly.

"Why did you not do the experiment at St. Barts… where there are proper safety measures in place?" her voice held an inch of steel.

"Because those people you work with are barely competent. They are lab monkeys, only good for pressing the buttons they have been told to press. Nothing here is dangerous Molly, you know that." He reasoned.

Her face started turning a slight shade of blush, "That isn't the point Sherlock. The point is that you do NOT have the proper equipment to do this!

Sherlock could see that her anger was mounting, "Molly, I am using the proper equipment. I got it from Barts. You are worrying for nothing."

That was the wrong thing to say apparently as her face got redder and her jaw clenched. "That's another thing Sherlock. You can't take equipment from Barts. Especially distillation flasks! "

"Why not?" He was genuinely confused by her statement.

"Because we have to keep a record of everything Sherlock and I am the one in charge of it. We have to account for all the distillation flasks and it starts to look suspicious if too many break or go missing!"

"Why? It's just glassware. Disposable really." Even though he didn't see the point of her anger and he was curious he was starting to enjoy riling her up.

"We have to keep track of them for precisely the reason you are using them! People will take them and use them for other, more illegal actions! You could get me in a lot of trouble for this Sherlock!" Her voice had risen slightly in pitch.

"I was going to return it Molly."

"That's beside the point!"

"Molly, I had everything under control. Nothing was going to happen. You are getting worked up." He said, attempting to calm her down.

"Worked up?! You have no regards to safety standards! How could you be so dense! You aren't even wearing safety goggles! What if your oil bath got a hot spot and cause a huge temperature influx, or some vapors caught on fire! You could have endangered not only yourself but the entire building! Do you know what happens when glass explodes Sherlock? You get shards embedded into your skin! You should always be using a fume hood when working with volatile chemicals!" By the end her voice had started to squeak, showing him just how angry she was.

He actually found the whole thing endearing. His little mouse was quite adorable when she got flustered at him. Yes, it appeared that his subconscious had decided to give her a pet name. She always called herself mousy, something he hated, but the fact she started squeaking towards the end of her rant just begged him to make the term something sentimental and all his own.

He also noticed that the flush of her skin began creeping down her neck and he wanted to see how far it could go. It was only for reference purposes, of course, so that later he could set a scale in his mind palace and know to what degree he angered her in the future. That is what he told himself anyways. He chose to not think about how much he wanted to see that flush bloom across her collar, begging him to sink his teeth into.

These thoughts had been plaguing his sleep for months now and he was finding it harder to push them away during his waking hours. His dreams were filled with feverish kisses and biting, awakening desire he hadn't felt since his early twenties. It didn't help that Molly had a habit of biting her lower lip all the time. It just reminded him of his dreams. How he wanted to replace those teeth with his, biting and suckling her lips, letting his teeth trace along her skin, nipping as he went. Yes, he attributed that horrible habit of hers to his apparent biting fetish and why he could never look away from her lips.

The line between dreams and reality blurred and he desperately wanted them to merge so he was going to see just how far he could push her.

"I fail to see your argument. I am better than most of the staff at St. Barts and if they manage to go this long without blowing something up…"

"Sherlock, there are rules in place for a reason. You have to follow them if you are going to use our facilities. I am already bending the rules so you can take body parts!" Her voice had lowered slightly but she was still angry enough that her skin was that delicious shade of red.

"Rules were made by imbeciles who are trying to impede real science by mounting paperwork on those who are competent. Which, I might add, is why you can't fulfill your full potential Molly. You are required to do too much paperwork."

"I have to do so much paperwork to cover your behind! People have to learn to work together, Sherlock, and when you are working with a group you need a set of standards to keep everyone on the same page!" She had started to step towards him as he achieved success in getting the flush to go further down her skin. It covered her chest, all that was exposed. His eyes fixated on her collarbone, his lips tingling.

"Did you hear a word I said Sherlock?!"

His gaze was broken and when he looked up he could see she was standing directly in front of him. "Yes. I did. But you fail to realize one important aspect, Molly Hooper." He said, smirking.

"And what is that? That you will call your brother and override everything that I say? That I will be hit with more paperwork thanks to you and you wanting to run what could have the potential to be a drug den in your apartment?!" Her voice got squeaky again.

He dropped his head to whisper in her ear, "No, that I only want to work with you. That is why I am not at Barts, because you are not there today." He with that he met her lips in a searing kiss. She gave a final squeak, which caused his to chuckle, before throwing her arms around his neck and returning his kiss passionately.

His mind was flooded with oxytocin as his arousal only deepened. He groaned into her mouth as their lips released and he began nipping at her jaw. Her moan threw his mind into instinct and he bent down, wrapping his arms underneath her butt. He picked her up and placed her on the table before moving down and biting on her collarbone. It was just as he imagined; just how it tasted in his dreams, sweet with a little bit of salt sweat but all Molly. He spent some time memorizing the curve of the bone, which spots caused her to squeak in delight before meeting her lips in another passionate kiss.

The continued snogging for what seemed to be ages, her hands running along the planes of his stomach before they finally had to break apart for air. Her lips were pleasantly swollen, her neck and shoulders had marks scattered across where he sucked and nibble at her skin. Her eyes were shining with delight and lust. She looked beautiful.

"You know you still have to return the equipment."


End file.
